Sandvik 3R60™

Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Sandvik materials.

Sandvik 3R60™ is an austenitic chromium-nickel steel with minimum 2.5% molybdenum and a low carbon content.

Chemical composition (nominal) %

Forms of supply

Seamless tube and pipe- Finishes and dimensions

Seamless tube and pipe in Sandvik 3R60™ is supplied in dimensions up to 260 mm outside diameter in the solution annealed and white-pickled condition or solution annealed in a bright-annealing process.

Other forms of supply

We can also deliver other product forms from stock in a grade corresponding to ASTM 316L mainly:

Welded tube and pipe

Fittings and flanges

Bar steel

Sizes in stock

Seamless tube is stocked in a wide range of sizes according to ISO. Heat exchanger and instrumentation tubes are also stocked in BWG-and SWG-sizes. Hollow bar is stocked in a large number of sizes as SANMAC 316L (see data sheet S-1840-ENG). Details of our manufacturing programme are given in catalogue S-110-ENG.

Mechanical properties

For tube and pipe with wall thickness greater than 10 mm (0.4 in.) the proof strength may fall short of the stated values by about 10 MPa (1.4 ksi).

At 20°C

Metric units

Proof strength

Tensile strength

Elong.

Hardness

Rp0.2a

Rp1.0a

Rm

Ab

A2"

MPa

MPa

MPa

%

%

HRB

≥220

≥250

515-690

≥40c

≥35

≤80

At 68°F

Imperial units

Proof strength

Tensile strength

Elong.

Hardness

Rp0.2a

Rp1.0a

Rm

Ab

A2"

ksi

ksi

ksi

%

%

HRB

≥32

≥36

75-100

≥40c

≥35

≤80

1 MPa = 1 N/mm2a) Rp0.2 and Rp1.0 correspond to 0.2% offset and 1.0% offset yield strength, respectively.b) Based on L0 = 5.65 √S0 where L0 is the original gauge length and S0 the original cross-section area.c) NFA 49-117, 49-217 with min 45% can be fulfilled on request.

Impact strength

Due to its austenitic microstructure, Sandvik 3R60 has very good impact strength both at room temperature and at cryogenic temperatures.

Corrosion resistance

Inorganic acids, e.g. phosphoric and sulfuric acids, at moderate concentrations and temperatures. The steel can also be used in sulfuric acid of concentrations above 90% at low temperature.

Salt solutions, e.g. sulfates, sulfides and sulfites

Caustic environments

Stress corrosion cracking

Austenitic steels are susceptible to stress corrosion cracking. This may occur at temperatures above about 60°C (140°F) if the steel is subjected to tensile stresses and at the same time comes into contact with certain solutions, particularly those containing chlorides. Such service conditions should therefore be avoided. Conditions when plants are shut down must also be considered, as the condensates which are then formed can develop conditions that lead to both stress corrosion cracking and pitting.

In applications demanding high resistance to stress corrosion cracking, austenitic-ferritic steels, such as Sandvik SAF 2304® or SAF 2205™ are recommended. See data sheets S-1871-ENG and S-1874-ENG.

Intergranular corrosion

Sandvik 3R60™ has a low carbon content and therefore better resistance to intergranular corrosion than steels of type AISI 316. The TTC-diagram, Figure 1, shows the result of corrosion testing for 24 hours in boiling Strauss solution (12% sulfuric acid, 6% copper sulphate). The resistance to grain boundary attack is much better for AISI 316L than for AISI 316. This is an advantage in complicated welding operations.

Figure 1. TTC-diagram for Sandvik 3R60 (AISI 316L) and AISI 316.

Pitting and crevice corrosion

Resistance to these types of corrosion improves with increasing molybdenum content. Sandvik 3R60™, containing about 2.6% Mo, has substantially higher resistance to attack than these steels of type AISI 304 and also better resistance than ordinary AISI 316/316L steels with 2.1% Mo.

Gas corrosion

Sandvik 3R60™ can be uses in

Air up to 850°C (1560°F)

Steam up to 750°C (1380°F)

Creep behavior should also be taken into account when using the steel in the creep range.

In flue gases containing sulfur, the corrosion resistance is reduced. In such environments the steel can be used at temperatures up to 600-750 °C (1100-1380 °F) depending on service conditions. Factors to consider are whether the atmosphere is oxidizing or reducing, i.e. the oxygen content, and whether impurities such as sodium and vanadium are present.

Heat treatment

Tubes are delivered in heat treated condition. If additional heat treatment is needed after further processing the following is recommended.

Stress relieving

850-950°C (1560-1740°F), cooling in air

Solution annealing

1000-1100°C (1830-2010°F), followed by rapid cooling in air or water.

Welding

The weldability of Sandvik 3R60TM is good. Welding must be carried out without preheating and subsequent heat treatment is normally not required. Suitable methods of fusion welding are manual metal-arc welding (MMA/SMAW) and gas-shielded arc welding, with the TIG/GTAW method as first choice.

For Sandvik 3R60TM, heat input of <2.0 kJ/mm and interpass temperature of <150°C (300°F) are recommended.

Bending

Annealing after cold bending is not normally necessary, but this point must be decided with regard to the degree of bending and the operating conditions. Heat treatment, if any, should take the form of stress relieving or solution annealing, see under Heat treatment.

Hot bending is carried out at 1100-850°C (2010-1560°F) and should be followed by solution annealing.

Applications

Sandvik 3R60™ is used for a wide range of industrial applications where steels of type ASTM 304 and 304L have insufficient corrosion resistance. Typical examples are: heat exchangers, condensers, pipelines, cooling and heating coils in the chemical, petrochemical, pulp and paper and food industries.

Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Sandvik materials.